Let the sunshine in

Mac clinic probes benefits of vitamin D

BY DIANE LU-HOVASSE | The homey,
turn-of-the-century house with the wraparound porch at 7 Maple Avenue is
unlike any other in Ste. Anne-de-Bellevue or Canada, in fact. Nestled inside
are overstuffed chairs, warm hardwood floors, a cozy fireplace and a Hologic
Discovery bone densitometer. This is the Mary Emily Clinical Nutrition
Research Unit, one of the best-kept secrets of McGill University's Dietetics
and Human Nutrition department.

Hope Weiler: Doing it for the kids Helen Rimmer

Adjacent to Macdonald campus and its Faculty of Agricultural and
Environmental Sciences, the former home of Walter and May Stewart was
renovated and opened in 1998 for clinical research. The unit was a generous
donation in 1995 from G. Stewart Brown in memory of his wife.

Since spring 2007, 40 breast-fed babies have been streaming through the house
for a three-year study to discover the optimal level of vitamin D. According
to Dr. Hope Weiler, Director of the Mary Emily, the Canadian Paediatrics
Society reported that rickets—a childhood disease usually associated with
developing countries—had recently reappeared in Canada.

"This showed the current recommendations for vitamin D are insufficient," she
says. At present, Health Canada states adequate amounts for people under 50
years is 200 IU daily, then doubles every 20 years, to a safe maximum of
2,000 IU.

Infants are considered deficient with less than 27 nanomoles/litre in their
blood. Rickets can appear as convulsions, respiratory distress, limb
deformity and delayed development. Adult insufficiency is associated
with autoimmune diseases, osteoporosis and cancer. Vitamin D is critical for
individuals with darker complexions because the melanin that pigments the
skin and acts as natural sunscreen also slows the skin's vitamin D-making
ability in the presence of ultraviolet light.

"Mothers with darker pigmented skin may not drink enough milk or be exposed
to enough sunlight to produce vitamin D in their bodies," notes Dr. Weiler.
"If they are deficient, they cann't pass enough of the vitamin through breast
milk to their babies." That's why rickets can appear in children from three
months to three years of age, she says. The Sunshine Vitamin study is not
looking at the minimal needed, she explains, but the ideal dose from infancy
for lifelong health.

"Each visit is 90 minutes," says Catherine Vanstone, Clinical Research
Coordinator and manager of the clinic. "We take the baby's weight, length and
head measurements each visit and the mother's weight and height." There are
also urine samples and a small blood sample from the baby's heel, as well as
a breast milk sample from the mother. Mothers are asked to log their food
consumption for three days prior to the visit. Their babies are provided with
vitamin D drops to be given every day and six clinical visits are scheduled
during their first year.

Dr. Weiler says they are still recruiting mothers and babies and wants to
find a total of 160 participants. "Our mission is to promote health early in
life," notes Dr. Weiler. "It's asking how much is the best for growth and how
can we optimize it. We want to set up people for good, lifelong health."